Portable grinder-mixers have come to relatively common use upon farms. They frequently use hammer mills to grind the feed and, at the same time, mix the ground material with other previously ground food or other additives utilized to enhance the quality of the endproduct. Examples of such efforts are seen in U.S. Pat. Nos. 3,129,927; 3,375,985; 3,133,727; 2,815,941; 3,254,878; 3,199,796; 2,236,219; 4,201,348; 4,092,004; 3,369,762; 2,894,733; and 3,840,189. These patents reflect a continuing and previously inadequately-met need for a portable grinder-mixer which will fully mix the ground feed and deliver same to various desired locations. One aspect of this inadequacy has been the characteristically high profile of such a vehicle, which precludes storage of the same within conventional storage buildings, because it is impossible to move such a tall vehicle through doorways of conventional height. The height of such a vehicle has heretofore been prohibitive in this sense, unless the volume thereof were reduced to a level below practical requirements. Moreover, the total mixing action which has been accomplished with such apparatus has, in general, been inadequate.